In recent years, mobile computing devices, such as portable digital assistants (PDAs), have become increasingly popular. These mobile devices are convenient to carry and allow the user to enter information at any desirable location, such as during a meeting, on an airplane, or in a hotel. The entered information is then often sent to a host computer that acts as a data collection device so that others may access it. Both the host computer and the mobile device run corresponding application programs to update each other's information.
This process of updating the information between the mobile device and the host computer is called "synchronization." In general, during synchronization, the remote device and the data collection device use a synchronization protocol to establish a communication path between them. After the communication path is established, a list of programs, sometimes referred to as conduits, are individually executed to update or "synchronize" the information in corresponding programs. Typically, the information to be synchronized resides in a database.
Currently, the synchronization may occur by connecting the mobile device to the data collection device through a modem, a local area network (LAN), or by placing the mobile device in a cradle which is connected directly to the data collection device. For example, FIG. 1 shows a system for synchronizing information that includes a mobile device 10, a cradle 14, and a data collection device 20. The mobile device 10 includes a serial computing port 12 that engages a serial connector port 16 on the cradle 14. The cradle 14 connects to the data collection device 20 by a serial cable 22. Activation of a sync button 18 on the cradle 14 initiates the synchronization process using a vendor-specific protocol that is layered on top of the well-known RS-232 protocol. One disadvantage of this system is that the mobile device 10 must be returned to the cradle 14 before synchronization can occur. Therefore, a user cannot synchronize their data from remote locations in a timely manner. Another disadvantage of this system is that the mobile device 10 expects a dedicated communication path to the data collection device 20. Therefore, synchronization data cannot be routed to a specific data collection device when there are multiple data collection devices available.
Another prior art system for synchronizing a mobile device with a data collection device is shown in FIG. 2. In this system, a modem attachment 24 is connected to the mobile unit 10 by coupling the serial computing port 12 to a serial connector port 16' located on the modem attachment 24. The modem is then connected to a telephone jack. Once connected, data may be transferred over an analog phone line 28 to a modem 26 that is coupled to the data collection device 20. One disadvantage of this system is that the modem attachment 24 typically cannot transmit data through a digital telephone exchange (PBX) that are often used to connect a number of telephones to the public switched telephone network (PSTN). Because these PBXs are becoming more and more widespread in offices and hotels around the world, the locations at which a user can transmit data from their mobile device 10 to the data collection device 20 have been correspondingly limited.
FIG. 3 shows yet another prior art system for synchronizing a mobile device with a data collection device. The system includes an Ethernet-based local area network (LAN) to which one or more data collection devices may be connected. A LAN attachment 30 having a serial connector port 16" is coupled with the serial computing port 12 on the mobile device 10 to allow data to be transferred between the mobile device 10 and one of a number of available data collection devices 20, 20', 20" over the LAN. Some disadvantages of this system include the additional cost of purchasing and installing cables for LAN ports and the additional space that these LAN ports occupy at each location where a user may wish to connect their mobile device in order to synchronize data.
Given the shortcomings in the prior art, there is a need for a system that allows a user to synchronize data between a mobile device at virtually any location through a commonly available digital telephone and PBX.